[Henry Krinkle]

Help!!!! I recently purchased a used CA and took it to the range today and had a less than positive experience. I only used PMC bronze 223 55 grain fmj ammo and shot through three types of mag's. I tried metal (non brand tried several) 30rd mags loaded with 5rd's & Therm-mold 30rd mags (several of them) and the crappy 10rd keltec (2 of them). Every mag that I tried had an issue.
Now my gripe isn't only based on the mags. I had several failure to seat ( with Therm-mold mag's primarily) when I released the bolt. Multiple fail to feeds after the first round which were primarily due to the rifle not extracting the spent shell casing from the recently fired round. When it did extract it would fail to feed the next round.
Prior to the trip to the range I cleaning the barrel, chamber and bolt face without removing the bolt and lightly oiled the piston. I did not remove the bolt or extractor. I tried to do a process of elimination by ruling out the mags so I would load one round & chamber it. When I did this it had a much better success rate extracting the casings with only two fail to extracts. Im open to any suggestions on how to resolve this. This was to be my primary rifle if the shtf and I now have feel like I have lost confidence in it. I want to like this rife I really do but am concerned and wondering what to do. I saw Bam Bam suggestion on removing the extractor and giving it a good cleaning as well as polishing the bolt and perhaps installing an Ar extractor. Any suggestions on mags? Thanks for your help in advance

 

[AO]

Well that does suck, sorry to hear.. Sorry I've no suggestions other than a good cleaning. My new CA should be arriving this week, so I've not shot one yet..hence the no suggestions part.
Good luck and let us know what fixes it.

 

[blakestree]

I think somewhere around 95% of the problems we hear about with new SU-16's can be attributed to the rifle not being cleaned properly before hitting the range. Obviously, that is not the case here. However, I'll suggest your used SU-16 might benefit from the same attention. Did yours come with the owner's manual? You should remove, strip, and clean the bolt assembly according to the instructions, therein. Inspect the extractor well, while you are at it. Although, I doubt it should need to be removed. Kel Tec advises against oiling the piston rod, tube, and spring, because of burn-off and fouling. I clean mine, thoroughly, and very lightly oil them, anyway. If I were you, I would make sure the piston head is completely free of fouling. This can be, next to cleaning the chamber, one of the most difficult chores in SU-16 maintenance. I soak mine in Hoppe's #9 and then hit it with a brass brush. Also, I'd inspect and run several pipe cleaners, soaked in solvent, through the gas block.

Furthermore, the PMC ammo should be just fine. Thermold magazines seem to have a reputation for being problematic, though I have no personal experience with them. I believe the Kel Tec 10rd mags have an unwarranted bad reputation, stemming from early versions having feed lips that were not reinforced. I, now, have four of them that I have no problems with. The only downside I find to them is that they will not drop free.

The most successfully used magazines tend to be USGI's with anti-tilt followers and Magpul P-Mags. I have a Troy BattleMag, too, that I'm perfectly happy with.

Good luck!

 

[Kent1955]

I agree. Not good for your confidence in the rifle. I can't add much more than A.O. did as far as a complete cleaning of the rifle. In my owners manual it mentions the o ring on the firing pin pin.They say not to use solvents on that pin. Solvents can damage the o ring used to hold it in place. When you take the bolt apart you will be able to feel the tension on the extractor and inspect it for any crud under it or damage to the hook that has to grab the rim of the cartridge. Push the ejector pin down to make sure it isn't binding. I use a thin wooden dowel to push the ejector pin down. It should be pretty stiff, but move freely.
Another point to check would be the hole in the barrel that goes to the gas piston. If whoever owned it shot real dirty ammo, I suppose that could get clogged up with carbon,copper or lead. I hope you find a easy fix to this Henry. I'm sure the more experienced folks on this site can assist if the simple cleaning & inspections don't work.

 

[3dogs]

My best guess is that a well used SU-16 might have a dirty piston. Is the piston coated with deposits or is it bare metal? Soak it in solvent and use an old brass brush to scrub off any deposits.

Sounds like you have some sort of friction problem that's sapping energy from the bolt when cycles. The bolt should cycle smoothly. Test for rough spots when you cycle it by hand. Also, using snap-caps may help identify the issue.

BTW, I doubt this is your problem, but I'm not sure I'd put oil on the piston itself. The heat may be too high for oil. You can lightly oil the piston rod.

Good luck,
3dogs

 

[Henry Krinkle]

Thanks for the suggestions guys. I'm going to clean like a..... and buy a couple of p-mags and see how it works. I'll also check the gas tube as suggested and clean the piston thoroughly. I have a crazy schedule but should be able to go back out to the range in two weeks and I'll let you all know. Thanks again for your help.

 

[Groo]

I'd never buy a used gun without shooting it first.
Can you get the seller to take it back? sounds like he dumped his problem instead of sending back to the factory to get it fixed, and that will be a more expensive option for the second owner.

 

[blakestree]

Or, maybe he just never cleaned it... I think it is too early to say something is wrong with the rifle.

 

[AO]

Or, maybe he just never cleaned it... I think it is too early to say something is wrong with the rifle.

I agree.. a GOOD cleaning might be all it needs..

 

[scrapperito]

I'm a newb, but I'll share a similar experience with a used CA. But my first time out after minor cleaning was using cheap russian Bear hollow point 223. Ftf, fte. Used lake city federal 5.56 FMJ and it was flawless.

 

[Groo]

he still has a bunch of mags that won't seat. I'm guessing all of the problems might be mag catch related.

 

[AO]

Hey Henry..just reread your original post...why do you think the stock mags are crappy?

 

[Henry Krinkle]

They don't drop free and one other two that I have won't hold all of the rounds well. They will actually pop out. The other holds it well.